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-rw-r--r--fs/jffs2/scan.c1182
1 files changed, 1182 insertions, 0 deletions
diff --git a/fs/jffs2/scan.c b/fs/jffs2/scan.c
new file mode 100644
index 000000000..29671e33a
--- /dev/null
+++ b/fs/jffs2/scan.c
@@ -0,0 +1,1182 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2001-2007 Red Hat, Inc.
+ *
+ * Created by David Woodhouse <dwmw2@infradead.org>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <linux/pagemap.h>
+#include <linux/crc32.h>
+#include <linux/compiler.h>
+#include "nodelist.h"
+#include "summary.h"
+#include "debug.h"
+
+#define DEFAULT_EMPTY_SCAN_SIZE 256
+
+#define noisy_printk(noise, fmt, ...) \
+do { \
+ if (*(noise)) { \
+ pr_notice(fmt, ##__VA_ARGS__); \
+ (*(noise))--; \
+ if (!(*(noise))) \
+ pr_notice("Further such events for this erase block will not be printed\n"); \
+ } \
+} while (0)
+
+static uint32_t pseudo_random;
+
+static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
+ unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s);
+
+/* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
+ * Returning an error will abort the mount - bad checksums etc. should just mark the space
+ * as dirty.
+ */
+static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
+ struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s);
+static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
+ struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s);
+
+static inline int min_free(struct jffs2_sb_info *c)
+{
+ uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
+#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
+ if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
+ return c->wbuf_pagesize;
+#endif
+ return min;
+
+}
+
+static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
+ if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
+ return sector_size;
+ else
+ return DEFAULT_EMPTY_SCAN_SIZE;
+}
+
+static int file_dirty(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
+{
+ int ret;
+
+ if ((ret = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
+ return ret;
+ if ((ret = jffs2_scan_dirty_space(c, jeb, jeb->free_size)))
+ return ret;
+ /* Turned wasted size into dirty, since we apparently
+ think it's recoverable now. */
+ jeb->dirty_size += jeb->wasted_size;
+ c->dirty_size += jeb->wasted_size;
+ c->wasted_size -= jeb->wasted_size;
+ jeb->wasted_size = 0;
+ if (VERYDIRTY(c, jeb->dirty_size)) {
+ list_add(&jeb->list, &c->very_dirty_list);
+ } else {
+ list_add(&jeb->list, &c->dirty_list);
+ }
+ return 0;
+}
+
+int jffs2_scan_medium(struct jffs2_sb_info *c)
+{
+ int i, ret;
+ uint32_t empty_blocks = 0, bad_blocks = 0;
+ unsigned char *flashbuf = NULL;
+ uint32_t buf_size = 0;
+ struct jffs2_summary *s = NULL; /* summary info collected by the scan process */
+#ifndef __ECOS
+ size_t pointlen, try_size;
+
+ ret = mtd_point(c->mtd, 0, c->mtd->size, &pointlen,
+ (void **)&flashbuf, NULL);
+ if (!ret && pointlen < c->mtd->size) {
+ /* Don't muck about if it won't let us point to the whole flash */
+ jffs2_dbg(1, "MTD point returned len too short: 0x%zx\n",
+ pointlen);
+ mtd_unpoint(c->mtd, 0, pointlen);
+ flashbuf = NULL;
+ }
+ if (ret && ret != -EOPNOTSUPP)
+ jffs2_dbg(1, "MTD point failed %d\n", ret);
+#endif
+ if (!flashbuf) {
+ /* For NAND it's quicker to read a whole eraseblock at a time,
+ apparently */
+ if (jffs2_cleanmarker_oob(c))
+ try_size = c->sector_size;
+ else
+ try_size = PAGE_SIZE;
+
+ jffs2_dbg(1, "Trying to allocate readbuf of %zu "
+ "bytes\n", try_size);
+
+ flashbuf = mtd_kmalloc_up_to(c->mtd, &try_size);
+ if (!flashbuf)
+ return -ENOMEM;
+
+ jffs2_dbg(1, "Allocated readbuf of %zu bytes\n",
+ try_size);
+
+ buf_size = (uint32_t)try_size;
+ }
+
+ if (jffs2_sum_active()) {
+ s = kzalloc(sizeof(struct jffs2_summary), GFP_KERNEL);
+ if (!s) {
+ JFFS2_WARNING("Can't allocate memory for summary\n");
+ ret = -ENOMEM;
+ goto out_buf;
+ }
+ }
+
+ for (i=0; i<c->nr_blocks; i++) {
+ struct jffs2_eraseblock *jeb = &c->blocks[i];
+
+ cond_resched();
+
+ /* reset summary info for next eraseblock scan */
+ jffs2_sum_reset_collected(s);
+
+ ret = jffs2_scan_eraseblock(c, jeb, buf_size?flashbuf:(flashbuf+jeb->offset),
+ buf_size, s);
+
+ if (ret < 0)
+ goto out;
+
+ jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
+
+ /* Now decide which list to put it on */
+ switch(ret) {
+ case BLK_STATE_ALLFF:
+ /*
+ * Empty block. Since we can't be sure it
+ * was entirely erased, we just queue it for erase
+ * again. It will be marked as such when the erase
+ * is complete. Meanwhile we still count it as empty
+ * for later checks.
+ */
+ empty_blocks++;
+ list_add(&jeb->list, &c->erase_pending_list);
+ c->nr_erasing_blocks++;
+ break;
+
+ case BLK_STATE_CLEANMARKER:
+ /* Only a CLEANMARKER node is valid */
+ if (!jeb->dirty_size) {
+ /* It's actually free */
+ list_add(&jeb->list, &c->free_list);
+ c->nr_free_blocks++;
+ } else {
+ /* Dirt */
+ jffs2_dbg(1, "Adding all-dirty block at 0x%08x to erase_pending_list\n",
+ jeb->offset);
+ list_add(&jeb->list, &c->erase_pending_list);
+ c->nr_erasing_blocks++;
+ }
+ break;
+
+ case BLK_STATE_CLEAN:
+ /* Full (or almost full) of clean data. Clean list */
+ list_add(&jeb->list, &c->clean_list);
+ break;
+
+ case BLK_STATE_PARTDIRTY:
+ /* Some data, but not full. Dirty list. */
+ /* We want to remember the block with most free space
+ and stick it in the 'nextblock' position to start writing to it. */
+ if (jeb->free_size > min_free(c) &&
+ (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
+ /* Better candidate for the next writes to go to */
+ if (c->nextblock) {
+ ret = file_dirty(c, c->nextblock);
+ if (ret)
+ goto out;
+ /* deleting summary information of the old nextblock */
+ jffs2_sum_reset_collected(c->summary);
+ }
+ /* update collected summary information for the current nextblock */
+ jffs2_sum_move_collected(c, s);
+ jffs2_dbg(1, "%s(): new nextblock = 0x%08x\n",
+ __func__, jeb->offset);
+ c->nextblock = jeb;
+ } else {
+ ret = file_dirty(c, jeb);
+ if (ret)
+ goto out;
+ }
+ break;
+
+ case BLK_STATE_ALLDIRTY:
+ /* Nothing valid - not even a clean marker. Needs erasing. */
+ /* For now we just put it on the erasing list. We'll start the erases later */
+ jffs2_dbg(1, "Erase block at 0x%08x is not formatted. It will be erased\n",
+ jeb->offset);
+ list_add(&jeb->list, &c->erase_pending_list);
+ c->nr_erasing_blocks++;
+ break;
+
+ case BLK_STATE_BADBLOCK:
+ jffs2_dbg(1, "Block at 0x%08x is bad\n", jeb->offset);
+ list_add(&jeb->list, &c->bad_list);
+ c->bad_size += c->sector_size;
+ c->free_size -= c->sector_size;
+ bad_blocks++;
+ break;
+ default:
+ pr_warn("%s(): unknown block state\n", __func__);
+ BUG();
+ }
+ }
+
+ /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
+ if (c->nextblock && (c->nextblock->dirty_size)) {
+ c->nextblock->wasted_size += c->nextblock->dirty_size;
+ c->wasted_size += c->nextblock->dirty_size;
+ c->dirty_size -= c->nextblock->dirty_size;
+ c->nextblock->dirty_size = 0;
+ }
+#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
+ if (!jffs2_can_mark_obsolete(c) && c->wbuf_pagesize && c->nextblock && (c->nextblock->free_size % c->wbuf_pagesize)) {
+ /* If we're going to start writing into a block which already
+ contains data, and the end of the data isn't page-aligned,
+ skip a little and align it. */
+
+ uint32_t skip = c->nextblock->free_size % c->wbuf_pagesize;
+
+ jffs2_dbg(1, "%s(): Skipping %d bytes in nextblock to ensure page alignment\n",
+ __func__, skip);
+ jffs2_prealloc_raw_node_refs(c, c->nextblock, 1);
+ jffs2_scan_dirty_space(c, c->nextblock, skip);
+ }
+#endif
+ if (c->nr_erasing_blocks) {
+ if (!c->used_size && !c->unchecked_size &&
+ ((c->nr_free_blocks+empty_blocks+bad_blocks) != c->nr_blocks || bad_blocks == c->nr_blocks)) {
+ pr_notice("Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
+ pr_notice("empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n",
+ empty_blocks, bad_blocks, c->nr_blocks);
+ ret = -EIO;
+ goto out;
+ }
+ spin_lock(&c->erase_completion_lock);
+ jffs2_garbage_collect_trigger(c);
+ spin_unlock(&c->erase_completion_lock);
+ }
+ ret = 0;
+ out:
+ jffs2_sum_reset_collected(s);
+ kfree(s);
+ out_buf:
+ if (buf_size)
+ kfree(flashbuf);
+#ifndef __ECOS
+ else
+ mtd_unpoint(c->mtd, 0, c->mtd->size);
+#endif
+ return ret;
+}
+
+static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, void *buf,
+ uint32_t ofs, uint32_t len)
+{
+ int ret;
+ size_t retlen;
+
+ ret = jffs2_flash_read(c, ofs, len, &retlen, buf);
+ if (ret) {
+ jffs2_dbg(1, "mtd->read(0x%x bytes from 0x%x) returned %d\n",
+ len, ofs, ret);
+ return ret;
+ }
+ if (retlen < len) {
+ jffs2_dbg(1, "Read at 0x%x gave only 0x%zx bytes\n",
+ ofs, retlen);
+ return -EIO;
+ }
+ return 0;
+}
+
+int jffs2_scan_classify_jeb(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb)
+{
+ if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
+ && (!jeb->first_node || !ref_next(jeb->first_node)) )
+ return BLK_STATE_CLEANMARKER;
+
+ /* move blocks with max 4 byte dirty space to cleanlist */
+ else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
+ c->dirty_size -= jeb->dirty_size;
+ c->wasted_size += jeb->dirty_size;
+ jeb->wasted_size += jeb->dirty_size;
+ jeb->dirty_size = 0;
+ return BLK_STATE_CLEAN;
+ } else if (jeb->used_size || jeb->unchecked_size)
+ return BLK_STATE_PARTDIRTY;
+ else
+ return BLK_STATE_ALLDIRTY;
+}
+
+#ifdef CONFIG_JFFS2_FS_XATTR
+static int jffs2_scan_xattr_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
+ struct jffs2_raw_xattr *rx, uint32_t ofs,
+ struct jffs2_summary *s)
+{
+ struct jffs2_xattr_datum *xd;
+ uint32_t xid, version, totlen, crc;
+ int err;
+
+ crc = crc32(0, rx, sizeof(struct jffs2_raw_xattr) - 4);
+ if (crc != je32_to_cpu(rx->node_crc)) {
+ JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
+ ofs, je32_to_cpu(rx->node_crc), crc);
+ if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
+ return err;
+ return 0;
+ }
+
+ xid = je32_to_cpu(rx->xid);
+ version = je32_to_cpu(rx->version);
+
+ totlen = PAD(sizeof(struct jffs2_raw_xattr)
+ + rx->name_len + 1 + je16_to_cpu(rx->value_len));
+ if (totlen != je32_to_cpu(rx->totlen)) {
+ JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%u\n",
+ ofs, je32_to_cpu(rx->totlen), totlen);
+ if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rx->totlen))))
+ return err;
+ return 0;
+ }
+
+ xd = jffs2_setup_xattr_datum(c, xid, version);
+ if (IS_ERR(xd))
+ return PTR_ERR(xd);
+
+ if (xd->version > version) {
+ struct jffs2_raw_node_ref *raw
+ = jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, NULL);
+ raw->next_in_ino = xd->node->next_in_ino;
+ xd->node->next_in_ino = raw;
+ } else {
+ xd->version = version;
+ xd->xprefix = rx->xprefix;
+ xd->name_len = rx->name_len;
+ xd->value_len = je16_to_cpu(rx->value_len);
+ xd->data_crc = je32_to_cpu(rx->data_crc);
+
+ jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, totlen, (void *)xd);
+ }
+
+ if (jffs2_sum_active())
+ jffs2_sum_add_xattr_mem(s, rx, ofs - jeb->offset);
+ dbg_xattr("scanning xdatum at %#08x (xid=%u, version=%u)\n",
+ ofs, xd->xid, xd->version);
+ return 0;
+}
+
+static int jffs2_scan_xref_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
+ struct jffs2_raw_xref *rr, uint32_t ofs,
+ struct jffs2_summary *s)
+{
+ struct jffs2_xattr_ref *ref;
+ uint32_t crc;
+ int err;
+
+ crc = crc32(0, rr, sizeof(*rr) - 4);
+ if (crc != je32_to_cpu(rr->node_crc)) {
+ JFFS2_WARNING("node CRC failed at %#08x, read=%#08x, calc=%#08x\n",
+ ofs, je32_to_cpu(rr->node_crc), crc);
+ if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rr->totlen)))))
+ return err;
+ return 0;
+ }
+
+ if (PAD(sizeof(struct jffs2_raw_xref)) != je32_to_cpu(rr->totlen)) {
+ JFFS2_WARNING("node length mismatch at %#08x, read=%u, calc=%zd\n",
+ ofs, je32_to_cpu(rr->totlen),
+ PAD(sizeof(struct jffs2_raw_xref)));
+ if ((err = jffs2_scan_dirty_space(c, jeb, je32_to_cpu(rr->totlen))))
+ return err;
+ return 0;
+ }
+
+ ref = jffs2_alloc_xattr_ref();
+ if (!ref)
+ return -ENOMEM;
+
+ /* BEFORE jffs2_build_xattr_subsystem() called,
+ * and AFTER xattr_ref is marked as a dead xref,
+ * ref->xid is used to store 32bit xid, xd is not used
+ * ref->ino is used to store 32bit inode-number, ic is not used
+ * Thoes variables are declared as union, thus using those
+ * are exclusive. In a similar way, ref->next is temporarily
+ * used to chain all xattr_ref object. It's re-chained to
+ * jffs2_inode_cache in jffs2_build_xattr_subsystem() correctly.
+ */
+ ref->ino = je32_to_cpu(rr->ino);
+ ref->xid = je32_to_cpu(rr->xid);
+ ref->xseqno = je32_to_cpu(rr->xseqno);
+ if (ref->xseqno > c->highest_xseqno)
+ c->highest_xseqno = (ref->xseqno & ~XREF_DELETE_MARKER);
+ ref->next = c->xref_temp;
+ c->xref_temp = ref;
+
+ jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(rr->totlen)), (void *)ref);
+
+ if (jffs2_sum_active())
+ jffs2_sum_add_xref_mem(s, rr, ofs - jeb->offset);
+ dbg_xattr("scan xref at %#08x (xid=%u, ino=%u)\n",
+ ofs, ref->xid, ref->ino);
+ return 0;
+}
+#endif
+
+/* Called with 'buf_size == 0' if buf is in fact a pointer _directly_ into
+ the flash, XIP-style */
+static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
+ unsigned char *buf, uint32_t buf_size, struct jffs2_summary *s) {
+ struct jffs2_unknown_node *node;
+ struct jffs2_unknown_node crcnode;
+ uint32_t ofs, prevofs, max_ofs;
+ uint32_t hdr_crc, buf_ofs, buf_len;
+ int err;
+ int noise = 0;
+
+
+#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
+ int cleanmarkerfound = 0;
+#endif
+
+ ofs = jeb->offset;
+ prevofs = jeb->offset - 1;
+
+ jffs2_dbg(1, "%s(): Scanning block at 0x%x\n", __func__, ofs);
+
+#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
+ if (jffs2_cleanmarker_oob(c)) {
+ int ret;
+
+ if (mtd_block_isbad(c->mtd, jeb->offset))
+ return BLK_STATE_BADBLOCK;
+
+ ret = jffs2_check_nand_cleanmarker(c, jeb);
+ jffs2_dbg(2, "jffs_check_nand_cleanmarker returned %d\n", ret);
+
+ /* Even if it's not found, we still scan to see
+ if the block is empty. We use this information
+ to decide whether to erase it or not. */
+ switch (ret) {
+ case 0: cleanmarkerfound = 1; break;
+ case 1: break;
+ default: return ret;
+ }
+ }
+#endif
+
+ if (jffs2_sum_active()) {
+ struct jffs2_sum_marker *sm;
+ void *sumptr = NULL;
+ uint32_t sumlen;
+
+ if (!buf_size) {
+ /* XIP case. Just look, point at the summary if it's there */
+ sm = (void *)buf + c->sector_size - sizeof(*sm);
+ if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
+ sumptr = buf + je32_to_cpu(sm->offset);
+ sumlen = c->sector_size - je32_to_cpu(sm->offset);
+ }
+ } else {
+ /* If NAND flash, read a whole page of it. Else just the end */
+ if (c->wbuf_pagesize)
+ buf_len = c->wbuf_pagesize;
+ else
+ buf_len = sizeof(*sm);
+
+ /* Read as much as we want into the _end_ of the preallocated buffer */
+ err = jffs2_fill_scan_buf(c, buf + buf_size - buf_len,
+ jeb->offset + c->sector_size - buf_len,
+ buf_len);
+ if (err)
+ return err;
+
+ sm = (void *)buf + buf_size - sizeof(*sm);
+ if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC) {
+ sumlen = c->sector_size - je32_to_cpu(sm->offset);
+ sumptr = buf + buf_size - sumlen;
+
+ /* sm->offset maybe wrong but MAGIC maybe right */
+ if (sumlen > c->sector_size)
+ goto full_scan;
+
+ /* Now, make sure the summary itself is available */
+ if (sumlen > buf_size) {
+ /* Need to kmalloc for this. */
+ sumptr = kmalloc(sumlen, GFP_KERNEL);
+ if (!sumptr)
+ return -ENOMEM;
+ memcpy(sumptr + sumlen - buf_len, buf + buf_size - buf_len, buf_len);
+ }
+ if (buf_len < sumlen) {
+ /* Need to read more so that the entire summary node is present */
+ err = jffs2_fill_scan_buf(c, sumptr,
+ jeb->offset + c->sector_size - sumlen,
+ sumlen - buf_len);
+ if (err) {
+ if (sumlen > buf_size)
+ kfree(sumptr);
+ return err;
+ }
+ }
+ }
+
+ }
+
+ if (sumptr) {
+ err = jffs2_sum_scan_sumnode(c, jeb, sumptr, sumlen, &pseudo_random);
+
+ if (buf_size && sumlen > buf_size)
+ kfree(sumptr);
+ /* If it returns with a real error, bail.
+ If it returns positive, that's a block classification
+ (i.e. BLK_STATE_xxx) so return that too.
+ If it returns zero, fall through to full scan. */
+ if (err)
+ return err;
+ }
+ }
+
+full_scan:
+ buf_ofs = jeb->offset;
+
+ if (!buf_size) {
+ /* This is the XIP case -- we're reading _directly_ from the flash chip */
+ buf_len = c->sector_size;
+ } else {
+ buf_len = EMPTY_SCAN_SIZE(c->sector_size);
+ err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);
+ if (err)
+ return err;
+ }
+
+ /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
+ ofs = 0;
+ max_ofs = EMPTY_SCAN_SIZE(c->sector_size);
+ /* Scan only EMPTY_SCAN_SIZE of 0xFF before declaring it's empty */
+ while(ofs < max_ofs && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
+ ofs += 4;
+
+ if (ofs == max_ofs) {
+#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
+ if (jffs2_cleanmarker_oob(c)) {
+ /* scan oob, take care of cleanmarker */
+ int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
+ jffs2_dbg(2, "jffs2_check_oob_empty returned %d\n",
+ ret);
+ switch (ret) {
+ case 0: return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
+ case 1: return BLK_STATE_ALLDIRTY;
+ default: return ret;
+ }
+ }
+#endif
+ jffs2_dbg(1, "Block at 0x%08x is empty (erased)\n",
+ jeb->offset);
+ if (c->cleanmarker_size == 0)
+ return BLK_STATE_CLEANMARKER; /* don't bother with re-erase */
+ else
+ return BLK_STATE_ALLFF; /* OK to erase if all blocks are like this */
+ }
+ if (ofs) {
+ jffs2_dbg(1, "Free space at %08x ends at %08x\n", jeb->offset,
+ jeb->offset + ofs);
+ if ((err = jffs2_prealloc_raw_node_refs(c, jeb, 1)))
+ return err;
+ if ((err = jffs2_scan_dirty_space(c, jeb, ofs)))
+ return err;
+ }
+
+ /* Now ofs is a complete physical flash offset as it always was... */
+ ofs += jeb->offset;
+
+ noise = 10;
+
+ dbg_summary("no summary found in jeb 0x%08x. Apply original scan.\n",jeb->offset);
+
+scan_more:
+ while(ofs < jeb->offset + c->sector_size) {
+
+ jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
+
+ /* Make sure there are node refs available for use */
+ err = jffs2_prealloc_raw_node_refs(c, jeb, 2);
+ if (err)
+ return err;
+
+ cond_resched();
+
+ if (ofs & 3) {
+ pr_warn("Eep. ofs 0x%08x not word-aligned!\n", ofs);
+ ofs = PAD(ofs);
+ continue;
+ }
+ if (ofs == prevofs) {
+ pr_warn("ofs 0x%08x has already been seen. Skipping\n",
+ ofs);
+ if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
+ return err;
+ ofs += 4;
+ continue;
+ }
+ prevofs = ofs;
+
+ if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
+ jffs2_dbg(1, "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n",
+ sizeof(struct jffs2_unknown_node),
+ jeb->offset, c->sector_size, ofs,
+ sizeof(*node));
+ if ((err = jffs2_scan_dirty_space(c, jeb, (jeb->offset + c->sector_size)-ofs)))
+ return err;
+ break;
+ }
+
+ if (buf_ofs + buf_len < ofs + sizeof(*node)) {
+ buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
+ jffs2_dbg(1, "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
+ sizeof(struct jffs2_unknown_node),
+ buf_len, ofs);
+ err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
+ if (err)
+ return err;
+ buf_ofs = ofs;
+ }
+
+ node = (struct jffs2_unknown_node *)&buf[ofs-buf_ofs];
+
+ if (*(uint32_t *)(&buf[ofs-buf_ofs]) == 0xffffffff) {
+ uint32_t inbuf_ofs;
+ uint32_t empty_start, scan_end;
+
+ empty_start = ofs;
+ ofs += 4;
+ scan_end = min_t(uint32_t, EMPTY_SCAN_SIZE(c->sector_size)/8, buf_len);
+
+ jffs2_dbg(1, "Found empty flash at 0x%08x\n", ofs);
+ more_empty:
+ inbuf_ofs = ofs - buf_ofs;
+ while (inbuf_ofs < scan_end) {
+ if (unlikely(*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff)) {
+ pr_warn("Empty flash at 0x%08x ends at 0x%08x\n",
+ empty_start, ofs);
+ if ((err = jffs2_scan_dirty_space(c, jeb, ofs-empty_start)))
+ return err;
+ goto scan_more;
+ }
+
+ inbuf_ofs+=4;
+ ofs += 4;
+ }
+ /* Ran off end. */
+ jffs2_dbg(1, "Empty flash to end of buffer at 0x%08x\n",
+ ofs);
+
+ /* If we're only checking the beginning of a block with a cleanmarker,
+ bail now */
+ if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
+ c->cleanmarker_size && !jeb->dirty_size && !ref_next(jeb->first_node)) {
+ jffs2_dbg(1, "%d bytes at start of block seems clean... assuming all clean\n",
+ EMPTY_SCAN_SIZE(c->sector_size));
+ return BLK_STATE_CLEANMARKER;
+ }
+ if (!buf_size && (scan_end != buf_len)) {/* XIP/point case */
+ scan_end = buf_len;
+ goto more_empty;
+ }
+
+ /* See how much more there is to read in this eraseblock... */
+ buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
+ if (!buf_len) {
+ /* No more to read. Break out of main loop without marking
+ this range of empty space as dirty (because it's not) */
+ jffs2_dbg(1, "Empty flash at %08x runs to end of block. Treating as free_space\n",
+ empty_start);
+ break;
+ }
+ /* point never reaches here */
+ scan_end = buf_len;
+ jffs2_dbg(1, "Reading another 0x%x at 0x%08x\n",
+ buf_len, ofs);
+ err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
+ if (err)
+ return err;
+ buf_ofs = ofs;
+ goto more_empty;
+ }
+
+ if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
+ pr_warn("Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n",
+ ofs);
+ if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
+ return err;
+ ofs += 4;
+ continue;
+ }
+ if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
+ jffs2_dbg(1, "Dirty bitmask at 0x%08x\n", ofs);
+ if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
+ return err;
+ ofs += 4;
+ continue;
+ }
+ if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
+ pr_warn("Old JFFS2 bitmask found at 0x%08x\n", ofs);
+ pr_warn("You cannot use older JFFS2 filesystems with newer kernels\n");
+ if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
+ return err;
+ ofs += 4;
+ continue;
+ }
+ if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
+ /* OK. We're out of possibilities. Whinge and move on */
+ noisy_printk(&noise, "%s(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
+ __func__,
+ JFFS2_MAGIC_BITMASK, ofs,
+ je16_to_cpu(node->magic));
+ if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
+ return err;
+ ofs += 4;
+ continue;
+ }
+ /* We seem to have a node of sorts. Check the CRC */
+ crcnode.magic = node->magic;
+ crcnode.nodetype = cpu_to_je16( je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE);
+ crcnode.totlen = node->totlen;
+ hdr_crc = crc32(0, &crcnode, sizeof(crcnode)-4);
+
+ if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
+ noisy_printk(&noise, "%s(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n",
+ __func__,
+ ofs, je16_to_cpu(node->magic),
+ je16_to_cpu(node->nodetype),
+ je32_to_cpu(node->totlen),
+ je32_to_cpu(node->hdr_crc),
+ hdr_crc);
+ if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
+ return err;
+ ofs += 4;
+ continue;
+ }
+
+ if (ofs + je32_to_cpu(node->totlen) > jeb->offset + c->sector_size) {
+ /* Eep. Node goes over the end of the erase block. */
+ pr_warn("Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
+ ofs, je32_to_cpu(node->totlen));
+ pr_warn("Perhaps the file system was created with the wrong erase size?\n");
+ if ((err = jffs2_scan_dirty_space(c, jeb, 4)))
+ return err;
+ ofs += 4;
+ continue;
+ }
+
+ if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
+ /* Wheee. This is an obsoleted node */
+ jffs2_dbg(2, "Node at 0x%08x is obsolete. Skipping\n",
+ ofs);
+ if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
+ return err;
+ ofs += PAD(je32_to_cpu(node->totlen));
+ continue;
+ }
+
+ switch(je16_to_cpu(node->nodetype)) {
+ case JFFS2_NODETYPE_INODE:
+ if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
+ buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
+ jffs2_dbg(1, "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
+ sizeof(struct jffs2_raw_inode),
+ buf_len, ofs);
+ err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
+ if (err)
+ return err;
+ buf_ofs = ofs;
+ node = (void *)buf;
+ }
+ err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs, s);
+ if (err) return err;
+ ofs += PAD(je32_to_cpu(node->totlen));
+ break;
+
+ case JFFS2_NODETYPE_DIRENT:
+ if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
+ buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
+ jffs2_dbg(1, "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
+ je32_to_cpu(node->totlen), buf_len,
+ ofs);
+ err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
+ if (err)
+ return err;
+ buf_ofs = ofs;
+ node = (void *)buf;
+ }
+ err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs, s);
+ if (err) return err;
+ ofs += PAD(je32_to_cpu(node->totlen));
+ break;
+
+#ifdef CONFIG_JFFS2_FS_XATTR
+ case JFFS2_NODETYPE_XATTR:
+ if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
+ buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
+ jffs2_dbg(1, "Fewer than %d bytes (xattr node) left to end of buf. Reading 0x%x at 0x%08x\n",
+ je32_to_cpu(node->totlen), buf_len,
+ ofs);
+ err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
+ if (err)
+ return err;
+ buf_ofs = ofs;
+ node = (void *)buf;
+ }
+ err = jffs2_scan_xattr_node(c, jeb, (void *)node, ofs, s);
+ if (err)
+ return err;
+ ofs += PAD(je32_to_cpu(node->totlen));
+ break;
+ case JFFS2_NODETYPE_XREF:
+ if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
+ buf_len = min_t(uint32_t, buf_size, jeb->offset + c->sector_size - ofs);
+ jffs2_dbg(1, "Fewer than %d bytes (xref node) left to end of buf. Reading 0x%x at 0x%08x\n",
+ je32_to_cpu(node->totlen), buf_len,
+ ofs);
+ err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
+ if (err)
+ return err;
+ buf_ofs = ofs;
+ node = (void *)buf;
+ }
+ err = jffs2_scan_xref_node(c, jeb, (void *)node, ofs, s);
+ if (err)
+ return err;
+ ofs += PAD(je32_to_cpu(node->totlen));
+ break;
+#endif /* CONFIG_JFFS2_FS_XATTR */
+
+ case JFFS2_NODETYPE_CLEANMARKER:
+ jffs2_dbg(1, "CLEANMARKER node found at 0x%08x\n", ofs);
+ if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
+ pr_notice("CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
+ ofs, je32_to_cpu(node->totlen),
+ c->cleanmarker_size);
+ if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
+ return err;
+ ofs += PAD(sizeof(struct jffs2_unknown_node));
+ } else if (jeb->first_node) {
+ pr_notice("CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n",
+ ofs, jeb->offset);
+ if ((err = jffs2_scan_dirty_space(c, jeb, PAD(sizeof(struct jffs2_unknown_node)))))
+ return err;
+ ofs += PAD(sizeof(struct jffs2_unknown_node));
+ } else {
+ jffs2_link_node_ref(c, jeb, ofs | REF_NORMAL, c->cleanmarker_size, NULL);
+
+ ofs += PAD(c->cleanmarker_size);
+ }
+ break;
+
+ case JFFS2_NODETYPE_PADDING:
+ if (jffs2_sum_active())
+ jffs2_sum_add_padding_mem(s, je32_to_cpu(node->totlen));
+ if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
+ return err;
+ ofs += PAD(je32_to_cpu(node->totlen));
+ break;
+
+ default:
+ switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
+ case JFFS2_FEATURE_ROCOMPAT:
+ pr_notice("Read-only compatible feature node (0x%04x) found at offset 0x%08x\n",
+ je16_to_cpu(node->nodetype), ofs);
+ c->flags |= JFFS2_SB_FLAG_RO;
+ if (!(jffs2_is_readonly(c)))
+ return -EROFS;
+ if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
+ return err;
+ ofs += PAD(je32_to_cpu(node->totlen));
+ break;
+
+ case JFFS2_FEATURE_INCOMPAT:
+ pr_notice("Incompatible feature node (0x%04x) found at offset 0x%08x\n",
+ je16_to_cpu(node->nodetype), ofs);
+ return -EINVAL;
+
+ case JFFS2_FEATURE_RWCOMPAT_DELETE:
+ jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n",
+ je16_to_cpu(node->nodetype), ofs);
+ if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(node->totlen)))))
+ return err;
+ ofs += PAD(je32_to_cpu(node->totlen));
+ break;
+
+ case JFFS2_FEATURE_RWCOMPAT_COPY: {
+ jffs2_dbg(1, "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n",
+ je16_to_cpu(node->nodetype), ofs);
+
+ jffs2_link_node_ref(c, jeb, ofs | REF_PRISTINE, PAD(je32_to_cpu(node->totlen)), NULL);
+
+ /* We can't summarise nodes we don't grok */
+ jffs2_sum_disable_collecting(s);
+ ofs += PAD(je32_to_cpu(node->totlen));
+ break;
+ }
+ }
+ }
+ }
+
+ if (jffs2_sum_active()) {
+ if (PAD(s->sum_size + JFFS2_SUMMARY_FRAME_SIZE) > jeb->free_size) {
+ dbg_summary("There is not enough space for "
+ "summary information, disabling for this jeb!\n");
+ jffs2_sum_disable_collecting(s);
+ }
+ }
+
+ jffs2_dbg(1, "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x, wasted 0x%08x\n",
+ jeb->offset, jeb->free_size, jeb->dirty_size,
+ jeb->unchecked_size, jeb->used_size, jeb->wasted_size);
+
+ /* mark_node_obsolete can add to wasted !! */
+ if (jeb->wasted_size) {
+ jeb->dirty_size += jeb->wasted_size;
+ c->dirty_size += jeb->wasted_size;
+ c->wasted_size -= jeb->wasted_size;
+ jeb->wasted_size = 0;
+ }
+
+ return jffs2_scan_classify_jeb(c, jeb);
+}
+
+struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
+{
+ struct jffs2_inode_cache *ic;
+
+ ic = jffs2_get_ino_cache(c, ino);
+ if (ic)
+ return ic;
+
+ if (ino > c->highest_ino)
+ c->highest_ino = ino;
+
+ ic = jffs2_alloc_inode_cache();
+ if (!ic) {
+ pr_notice("%s(): allocation of inode cache failed\n", __func__);
+ return NULL;
+ }
+ memset(ic, 0, sizeof(*ic));
+
+ ic->ino = ino;
+ ic->nodes = (void *)ic;
+ jffs2_add_ino_cache(c, ic);
+ if (ino == 1)
+ ic->pino_nlink = 1;
+ return ic;
+}
+
+static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
+ struct jffs2_raw_inode *ri, uint32_t ofs, struct jffs2_summary *s)
+{
+ struct jffs2_inode_cache *ic;
+ uint32_t crc, ino = je32_to_cpu(ri->ino);
+
+ jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
+
+ /* We do very little here now. Just check the ino# to which we should attribute
+ this node; we can do all the CRC checking etc. later. There's a tradeoff here --
+ we used to scan the flash once only, reading everything we want from it into
+ memory, then building all our in-core data structures and freeing the extra
+ information. Now we allow the first part of the mount to complete a lot quicker,
+ but we have to go _back_ to the flash in order to finish the CRC checking, etc.
+ Which means that the _full_ amount of time to get to proper write mode with GC
+ operational may actually be _longer_ than before. Sucks to be me. */
+
+ /* Check the node CRC in any case. */
+ crc = crc32(0, ri, sizeof(*ri)-8);
+ if (crc != je32_to_cpu(ri->node_crc)) {
+ pr_notice("%s(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
+ __func__, ofs, je32_to_cpu(ri->node_crc), crc);
+ /*
+ * We believe totlen because the CRC on the node
+ * _header_ was OK, just the node itself failed.
+ */
+ return jffs2_scan_dirty_space(c, jeb,
+ PAD(je32_to_cpu(ri->totlen)));
+ }
+
+ ic = jffs2_get_ino_cache(c, ino);
+ if (!ic) {
+ ic = jffs2_scan_make_ino_cache(c, ino);
+ if (!ic)
+ return -ENOMEM;
+ }
+
+ /* Wheee. It worked */
+ jffs2_link_node_ref(c, jeb, ofs | REF_UNCHECKED, PAD(je32_to_cpu(ri->totlen)), ic);
+
+ jffs2_dbg(1, "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
+ je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
+ je32_to_cpu(ri->offset),
+ je32_to_cpu(ri->offset)+je32_to_cpu(ri->dsize));
+
+ pseudo_random += je32_to_cpu(ri->version);
+
+ if (jffs2_sum_active()) {
+ jffs2_sum_add_inode_mem(s, ri, ofs - jeb->offset);
+ }
+
+ return 0;
+}
+
+static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
+ struct jffs2_raw_dirent *rd, uint32_t ofs, struct jffs2_summary *s)
+{
+ struct jffs2_full_dirent *fd;
+ struct jffs2_inode_cache *ic;
+ uint32_t checkedlen;
+ uint32_t crc;
+ int err;
+
+ jffs2_dbg(1, "%s(): Node at 0x%08x\n", __func__, ofs);
+
+ /* We don't get here unless the node is still valid, so we don't have to
+ mask in the ACCURATE bit any more. */
+ crc = crc32(0, rd, sizeof(*rd)-8);
+
+ if (crc != je32_to_cpu(rd->node_crc)) {
+ pr_notice("%s(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
+ __func__, ofs, je32_to_cpu(rd->node_crc), crc);
+ /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
+ if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
+ return err;
+ return 0;
+ }
+
+ pseudo_random += je32_to_cpu(rd->version);
+
+ /* Should never happen. Did. (OLPC trac #4184)*/
+ checkedlen = strnlen(rd->name, rd->nsize);
+ if (checkedlen < rd->nsize) {
+ pr_err("Dirent at %08x has zeroes in name. Truncating to %d chars\n",
+ ofs, checkedlen);
+ }
+ fd = jffs2_alloc_full_dirent(checkedlen+1);
+ if (!fd) {
+ return -ENOMEM;
+ }
+ memcpy(&fd->name, rd->name, checkedlen);
+ fd->name[checkedlen] = 0;
+
+ crc = crc32(0, fd->name, checkedlen);
+ if (crc != je32_to_cpu(rd->name_crc)) {
+ pr_notice("%s(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
+ __func__, ofs, je32_to_cpu(rd->name_crc), crc);
+ jffs2_dbg(1, "Name for which CRC failed is (now) '%s', ino #%d\n",
+ fd->name, je32_to_cpu(rd->ino));
+ jffs2_free_full_dirent(fd);
+ /* FIXME: Why do we believe totlen? */
+ /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
+ if ((err = jffs2_scan_dirty_space(c, jeb, PAD(je32_to_cpu(rd->totlen)))))
+ return err;
+ return 0;
+ }
+ ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
+ if (!ic) {
+ jffs2_free_full_dirent(fd);
+ return -ENOMEM;
+ }
+
+ fd->raw = jffs2_link_node_ref(c, jeb, ofs | dirent_node_state(rd),
+ PAD(je32_to_cpu(rd->totlen)), ic);
+
+ fd->next = NULL;
+ fd->version = je32_to_cpu(rd->version);
+ fd->ino = je32_to_cpu(rd->ino);
+ fd->nhash = full_name_hash(NULL, fd->name, checkedlen);
+ fd->type = rd->type;
+ jffs2_add_fd_to_list(c, fd, &ic->scan_dents);
+
+ if (jffs2_sum_active()) {
+ jffs2_sum_add_dirent_mem(s, rd, ofs - jeb->offset);
+ }
+
+ return 0;
+}
+
+static int count_list(struct list_head *l)
+{
+ uint32_t count = 0;
+ struct list_head *tmp;
+
+ list_for_each(tmp, l) {
+ count++;
+ }
+ return count;
+}
+
+/* Note: This breaks if list_empty(head). I don't care. You
+ might, if you copy this code and use it elsewhere :) */
+static void rotate_list(struct list_head *head, uint32_t count)
+{
+ struct list_head *n = head->next;
+
+ list_del(head);
+ while(count--) {
+ n = n->next;
+ }
+ list_add(head, n);
+}
+
+void jffs2_rotate_lists(struct jffs2_sb_info *c)
+{
+ uint32_t x;
+ uint32_t rotateby;
+
+ x = count_list(&c->clean_list);
+ if (x) {
+ rotateby = pseudo_random % x;
+ rotate_list((&c->clean_list), rotateby);
+ }
+
+ x = count_list(&c->very_dirty_list);
+ if (x) {
+ rotateby = pseudo_random % x;
+ rotate_list((&c->very_dirty_list), rotateby);
+ }
+
+ x = count_list(&c->dirty_list);
+ if (x) {
+ rotateby = pseudo_random % x;
+ rotate_list((&c->dirty_list), rotateby);
+ }
+
+ x = count_list(&c->erasable_list);
+ if (x) {
+ rotateby = pseudo_random % x;
+ rotate_list((&c->erasable_list), rotateby);
+ }
+
+ if (c->nr_erasing_blocks) {
+ rotateby = pseudo_random % c->nr_erasing_blocks;
+ rotate_list((&c->erase_pending_list), rotateby);
+ }
+
+ if (c->nr_free_blocks) {
+ rotateby = pseudo_random % c->nr_free_blocks;
+ rotate_list((&c->free_list), rotateby);
+ }
+}